The preliminary studies on multiple-input multiple-output (MIMO) capacity
showed that single-user MIMO capacity can be achieved by Gaussian
input signaling [1]}, [2]}. In [3]},
Weingarten et al. further proved that the entire capacity
region of a Gaussian MIMO broadcast channel (BC) is achievable through
optimal dirty paper coding (DPC) method. In reality, the optimal precoding
method is not only high-complexity but also difficult to implement.
As a result, there are growing interests in suboptimal techniques
such as zero-forcing (ZF) and successive zero-forcing dirty-paper
coding (SZFDPC) [4]}, [5]}, [6]}, [7]}, [8]}, [9]}.
